Colloid explosive and process of making the same.



J. EnNAnou.. CULLUID EXPLOSIVE AND PRUCESS 0F MAKING SAME.

(Apuasion med .1m 4, 1901.)

7 I No. 673,377. Patented May 7, |901- (.Nu Model.)

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SPECIFICATION forming part of Letters Patent No. 673,377, dated May 7, 1901. Application iled January 4, 1901. Serial. No. 42,064, (No specimens.)

To all whom, it may concern" Be it known that I, JOHN B. BERNADOU, lieutenant United States Navy, have invented certain new and useful Improvements in Colloids and Processes of Making the Same, of which the following is a specification'.

My invention relates to an im proved colloid which may be used after drying as a gunpowder or as an explosive cementing agent or binder in connection with other materials' used in the manufacture of smokeless powders, and to process for making the same. A

I have discovered that if insoluble nitrocellulose, which Ideine as nitrocellulose insoluble at ordinary atmospheric temperatures in a mixture of two parts, by weight, of ethylie ether and one part, by weight, of ethyl-alcohol and possessing a content of oxygen above that corresponding to the formula C12H,5O5(N03)5, be immersed in ethyl-ether and be exposed to a very low temperature, below that of freezing ethyl-alcohol ninetyfive per cent., by volume, absolute, it will go into solution or form a jelly with the ether, resulting in the formation of a colloid. Once in solution or jelly the insoluble nitrocellulose will not again revert to its original i form, but constitutes a body7 which may be employed when dried as a powder or as a cementing agent or binder in the manufacture of powders containing other ingredients.

The property of dissolving in ether in the presence of cold is common to all forms of nitrocellulose. I have hitherto called attention to the solubility of ether-alcohol-soluble nitrocellulose in ether alone in the presence of a moderate degree of cold, (see Letters Patent of the United States issued to me June 26, 1900, No. 652,455,) but now call attention to the solubility in ether alone of the highlyoxygenated or so-called insoluble varieties of nitrocellulose upon the application of more intense cold.

At present it is the general practice in the ymanufacture of colloid, smokeless powders -to mix the nitrocellulose with a colloiding agent, as acetone or ether-alcohol, to thor;

oughly mix them in a mechanical mixer and :to form the resultant pasty mass into the desired shapes7 as rods, strips, or grains, which are then exposed to the air or to a moderate heat until the excess of solvent is expelled.

The drying heat must bev regular and the drying conducted with care and uniformity. If the powder be dried too quickly, as by exposure to too great a heat, the surface of the grains will be formed into a pellicle, while part of the interior content of the solvent will vaporize, causing the grain to swell and split. i

If the powder be not dried uniformly, th

damper grains will ignite more slowly than the drier ones, and hence irregularity in ignition and ballistic performance will result. If the powder be left in an undried state, the

i ual solvent--that remaining after the pasty colloid has been formed into the linal shape-- can be driven off the more effective will be the powder, the greater its ballistic power, and the less 'the chance of hang-lires.

As heretofore employed in the manufacture of smokeless powders, insoluble nitrocellulose has been colloided in` acetone or in certain other solvents in which it dissolves with ease at ordinary atmospheric temperatures; but such colloids, being brittle, are unsuitable for use as smokeless powders, as they give rise to irregular bore-pressures on discharge of the gun.

I have found by experiment thatin the presence of a very intense degree of cold, below that required to freeze ethyl-alcohol ninetyfive per cent. absolute by volume, insoluble nitrocellulose can be made to dissolve in ethyl-ether alone. This action of insoluble nitrocellulose may easily be shown by placing a few tenths of a grain of some form of insoluble nitrocellulose-e. g., unpulped guncotton-in a test tube, pouring over 'the same ten or fifteen cubic centimeters of ethylic ether, closely corkin g the tube, and im mersing it in a bath of liquid air. By immersion in a bath of liquid air I mean immersion of the closed vessel containing the insoluble nitrocellulose and ether in a bath of liquid air and exposure of the said vessel to the action of IOO f cess, into a syrupy fluid.

I insoluble nitrocellulose to'mechanical action,

the liquidvair its contents' are reduced' "t @Imperative .below thatfof-v the freezius'f 1 poi'ntof ethylealcohol ninety-five per-cent. ab-

solute.v Upon allowing ythetube-to rernain ill f` the liquid-air bath a sucientlength of tinrxe,Y removing it, andallowing its'temperatureto' rise by contactwit-h thel atmosphere itn willy be found that the cotton has lost its fibrous structure andhas become converted iptofV a gelatinous body or, if the ether bein large ex'-l The ease with which the insoluble nitro, cellulose can be colloided in ether in the presence of cold is materially increased by mechanical agitation-that is, by kneading or incorporating the ether and insoluble nitrocellulose together in a closed vessel, whereby the colloid can bedeveloped by the expenditure of a minimum amount ofA solvent.

The process of forming the colloid powder therefore consists in subjecting the ether and agitation, or kneading in some approved form 'ofr'neohanical mixer-such as the Werner and Pfleiderer, with cover, which is herewith illustrated`which is surrounded in Whole or in part bya cooling-jacket.

Inu the drawing, d is a vessel furnished with a cover b, c revolving blades for mixing the materials, and d the cooling-jacket surround-v ing the vessel u..

It will be understood that I do not desire y to confine myself to thel use of the mixer herein shown, as any other suitable form of mixer may be used.

I am aware that insoluble nitrocellulose i has heretofore been colloided in the presence of great cold in the standard solution of etheralcohol-11.6., two parts, by weight, of ether to one part, by weight,of alcohol-but so far as I am aware this substance Vhas never before been colloided in ether alone.

As has before been stated, the nitrocellulose after being colloided has to'be dried before it can be used as a smokeless powder. The word dried is used by powder-makers relatively, as experience has shown that it is impossible to get rid of all traces of the solvent, even after long periods of exposure to 'whighiembemme-i @naamw @or 'ldidsare 'more difficult tel drythan an? ether colloid )on Lacco unt of tlie alcohol; which 4 is permitted `t` and v.always contain'sas` much ,loid contains,residually,V ether alone; bu't'as theetheris'niore volatilethan alcohol or waterit is possible to dry an ether colloid more sompleely than s ether-alcohol celled.

Y The nitrocellulose herein referred to as the lower'limit of the insoluble nitrocelluloses, CNHMONOQS, is the `cellulosepentanitrate of Eder.

Having thus described my invention, I claim as new and desire to secure by Letters Patent7 l. An ether colloid of ether-alcohol-insoluble nitrocellulose possessing a -content of `nitrogenl above that corresponding to the formula CHMONOSL.

2. The described method of forming a' colloid consisting in subjecting insoluble nitrocellulose and ether to a temperature below that of freezing ethyl-alcohol ninety-ive per cent. by volume absolute and in evaporating off the excess of solvent in the resultant product.

3. The described methodof forming a colloid consisting in subjecting insoluble nitrocellulose and ether,in a closed Vessel, to a temperature below that of freezing ethyl alcobol ninety-five per cent. by volume absolute and in evaporating off the excess of solvent in the resultant product.

4. The described process of manufacture of a colloid powder consisting in subjecting l insoluble nitrocellulose and ether in a closed vessel, to a temperature below that of freezing ethyl-alcohol ninety-five per cent. by Volume absolute, mechanically agitating or kneading the cooled mixture, forming it into shapes or grains and drying.

JOHN B. BERNADOU.

Witnesses HoMER M. BYINGTON,

O. J. HANCOCK. 

